Hydroxy-terminated polyether-based urethane compositions



United The present invention relates to novel branched hydroxy-terminated polyether-based urethane compositions which are useful as hydroxy-terminated urethane components for two-component polyurethane coatings or corresponding one package systems which employ as the other, or diisocyanate ingredient, a blocked isocyanate, and which are also of special utility as bodying agents for urethane coatings, particularly when it is not desired to employ thermoplastic resins for such purpose.

It is an object of the present invention to provide novel bodying agents for urethane coatings. It is a further object to provide novel and valuable branched hydroxyterminated urethane'components for polyurethane coatings systems. A further object is the provision of such compositions which are polyetherbased urethanes. Another object is the provision of such urethane compositions which lend advantageous properties to polyurethane coatings in which they are employed as the hydroxyterminated component or ingredient. Still another object of the invention is the provision of a process for the production of such urethane compositions by the reaction of about one molar proportion of a selected arylene diisocyanate with about two molar proportions of a selected polyether polyol, and the productsfthereby produced. Other objects of the invention will become apparent hereinafter.

The foregoing and additional objects are accomplished by the provision of branched urethane compositions of the following idealized formula:

f -CNH 0 L J, R wherein R is selected from hydrogen and methyl, wherein y is a number from zero to one, inclusive, and wherein Q is the same in both occurrences and is the radical of a branched polyether polyol (b), which is a propylene ordinary hydroxyl-bearing materials such as polyesters and regular polyols. Polyurethane coatings prepared therefrom by reaction with an isocyanate-terminated component dry to touch upon evaporation of solvent, and have considerably less sagging tendency than polyurethane coating formulations incorporating regular polyols. When the branched hydroxy-terminated urethane compositions of the present invention are reacted with an isocyanateterminated component, the resulting polyurethane surface coatings are characterized by properties which are superior to those obtained from the same isocyanate component and previously known poly-hydroxy components. The same is true when they are employed as one ingredient of a one package surface coating composition together with the a blocked diisocyanate as the other ingredient (for example, in baking enamels or wire coatings).

The branched hydroxy-terminated urethane compositions of the present invention are prepared by reacting about one molar proportion of anappropriate arylene diisocyanate' (a), selected from phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, including mixtures of 2,4 and 2,6-tolylene diisocyanates, and diphenylmethane-4,4-diisocyanate, with about two molar proportions of the selected branched polyether polyol (b) to produce a hydroxy-terminated urethane composition in which the terminal hydroxy groups are furnished by the polyether polyol molecule.

The branched polyether polyol (b) used in the reaction is a propylene oxide addition product of a lower alkanol, containing up to and including eight carbon atoms and containing at least three and not more than four hydroxy groups per molecule, and may be represented by the formula:

0-(G;Hfl0)nH zH4) a a) n.'OR' fl n Jz o-(o,H,o)nH

wherein R with attached oxygen atoms represents a loweralkanol radical, n is a number from one to three, inclusive, and x and z are individually numbers from zero to one, inclusive, and need not be the same. Representative branched polyether polyols encompassed by this formula include the addition products of glycerine, hexanetriol, and trimethylolpropane with from three to nine moles of propylene oxide, the addition products of such polyols further reacted with one mole of ethylene oxide, the addition product of pentaerythritol with from vfour to twelve moles of propylene oxide, the addition products of such polyols further reacted with one mole of ethylene oxide, and the like. The terminal ethylene oxide unit, when added to the polyoxypropylene chain or unit, pro vides a primary hydroxy group of relatively high reactivity for definite direction and precedence of reaction with NCO groups in preparing the OH-terminated urethane from the starting arylene diisocyanate (a).

In practice, the molecular weights of the branched-hydroxy-termiuated urethane compositions of the invention prepared in the given manner, have been found to be very close'to the molecular weight of a composition having an idealized structure, since very little polymerization occurs using predetermined molar proportions under moderate reaction conditions, viz., exclusion of moisture and initial reaction temperature, less than about 60 C. Also, in practice, a polyol having no more than about two propylene oxide units added per individual hydroxyl of starting polyol is usually preferred, and of the polyols, trimethyloh propane polyoxypropylene derivatives are preferred. 'As for the isocyanate employed, tolylene diisocyanate,usually a mixture of about /20% of the 2,4 and 2,6 isomers, is preferred for reasons of economy. Other variations in the starting materials to procure variations in the substituents of the branched hydroxy-terminated urethane compositions may be usefully made to obtain polyurethane surface coatings of varying types and characteristics upon reaction with a selected'polyisocyanate' component. For example, lengthening of the polyoxypropylene chains shown in the above formulae results in a polyurethane coating having a longer pot life, greater flexibility, and lower solvent resistance, while shortening of these polyoxypropylene chains has just the opposite eifect. Flexibility of such coatings can, for example, be readily adjusted by changing the length of the polyoxypropylene branches of the polyol (b), if desired. The preferred equivalent weight of the hydroxy-terminated urethanes of the present invention. is between about and 350.

, bothends of the molecule.

' I GENERAL PROCEDURE Hydroxy-terminated urethanes, such as OH-lof Example 1, are prepared by reacting together about one -tnole of the selected arylene diisocyanate and about two moles of polyether triol or tetraol in order to form a hydroxy-terminated urethane with free OH groups on The addition of two polyether triol molecules to the starting arylene diisocyanate makes the NCO/ OH ratio 1/3, while two polyether tetraol molecules makes the ratio 1/4. Dilution of the OH- terminated urethane,'if desired, may be with any suitable non-reactive surface coating solvent, or the reaction may be conducted in the presence of such a solvent. Many such solvents suitable in general for the urethane coatings and components thereof are known in the art, for example, 2-ethoxyethyl acetate, Z-methoxyethyl acetate, Z-butoxyethyl acetate, toluene, xylene, ethyl acetate, butyl acetate, amylacetate, other similar esters, ketones, chlorinated solvents, nitroaliphatic solvents, dioxane, and the like. In most instances no solvent is required during the reaction.

Polyether polyols used in the reaction are preferably stripped of water by azeotropic distillation with toluene. 'In this manner, the amount of water 'can be decreased from 0.08-0.15 to 0.02% or even less. A clean, dry, three-necked five-liter flask was used as a reaction vessel,

and a nitrogen blanket was maintained over the reactants.

I Example 1 '(OH-I) Reactants Moles Parts 7 Weight, percent Polyoxypropylene derivative of trimethylolpropane, 411, ,Pluracol PP-440 2 3,288 66 Tolylene diisocynate, TDI (80/2 2/4,

2 1 696 14 2-ethoxyethyl acetate 496 10 Xylene 496 10 Norm-Ratio of ractive groups: NCO/OH=2/6=1/3.

" Preparation of OH1: 3288 parts of Pluracol TP-440 and 696 parts of tolylene diisocyanate are charged into a -liter reaction flask and stirred gently. The temperature of the exothermic reaction rises to 60 C. The blend is kept-at this temperature for at least one hour until the exothermic reaction stops, whereafter 223 parts of 2 ethoxyethyl acetate and 223 parts of xylene are added in order to dilute the batch to 90% solids.

The temperature is then raised to 80 C. and the contents are heated for 3 hours witha gentle stirring. The

viscosities are measured each hour.

' Viscosity of the 90% solid batch reaches:

273 of 2-ethoxyethyl acetate and 273 parts of xylene are added in order to dilute the batch to 80% solids. The contents are bottled.

Properties of OH1:

NCO/0H l/3 Average'molecular weight 1000 Average equivalent weight 250 Hydroxyl number 224 Percent hydroxyl 6.8

Properties of 01-1-1 solution:

Non-volatile, percent Weight per gallon, lb. 8.78 Viscosity at 25 C., cps 500-2000 OH-l in urethant coatings: Two typical urethanecoah ing formulations are presented with hydroxy-terminated intermediate OH-l, as a second component.

TWO COMPONENT URETHANE COATINGS Formulation Composition Isocyanate-terminated intermediate..- 2 NC O-1 3 N C 0 3 Parts 101 162 Hydroxyl-terminated intermediat OH-l OH-l Parts 100 NCO/OH 1.2/1.0 1.2/1.0

1 Numerous other organic polyisocyanates can be used as well as NC 0- 1 and N 0 O-3, such as, for example, tri TDI adduct of trimethylolpropane or hexanetriol, the phenylurethanes of any of the foregoing, TDI, DI, and the like.

2 N 00-1 is the NCO-terminated reaction product of three moles of TDI with one mole of TP-440 polyol (propylene oxide addition product of trimethylolpropane having a M.W. otabout 410).

a NCO-3 is the NCO-terminated reaction product of two moles of NCO-1 with one mole of P-410 polylol (polypropylene glycol, M.W. about 410).

Formulation I Properties Ourin time:

D st free, hr- 1.5- 1.6. Dry to touch, hr 3.0 3.0. Pot life, hr 36 42. Sword hardness 48- 16-36. V Elongation, percent R 50-200. Tensile strength, p.s.i 4,000-8,000- 2,600-4,000. Impact test-Gardner, inch-1b.:

Dir 20 over 30 Indir 8 over 30 Chemical re i mum Exelllen Excellent. Solvent resistance, 11L: Toluene 4 4, 2-ethoxyethy1 ace 3. Methyl isobutyl ke rm 2. Water resistance:

Immersion 24 hr., 25 0 No effect-.. No effect. Immersion hr., 100 0 7 do Do. Weatherometer test, 500 hr No loss of No loss gloss.

' I gloss. I

Example 2 (OH-1A) Reactants Moles Parts TDI (80/20; 2,4I2,6) 1 174 Polyoxypropylene derivative of entaerythntol-d moles PO to 1 of PE (M.W. 484 2 968 2-ethoxyethyl acetate 249 Xylene 249 7 Preparation of OH-1A: Same as in Example 1.

Properties of OH-lA: I

. NCO/ OH g 1/4 Molecular Weight 1148 Equivalent weight 192 Hydroxyl number 293 OH-1A in urethane surface coatings; When employed as the second component together with NCO-1 or NCO-3 in the NCO/ OH proportions of Example 1, OH,1A gives urethane films which are less flexible but which have greater solvent resistance and greater hardness than the films of Example 1. Chemical resistance and water immersion resistance are excellent. 1

6 Example 3 greater solvent resistance and greater film hardness than the films of Example 1. Chemical resistance and water immersion resistance are excellent.

Reactants Moles Parts Example 6 TDI (so 2o; 2,4 2,a 1 174 (OH1Z) Polyoxypropylene derivative of trimethylolpropane (M i vi ri 2 616 Reactams M1BS Part3 2-ethoxyethyl acetate 99 99 1O TDI(80/20;2,4/2,6) 1 174 Addition product ol 8 moles of propylene oxide to V 1 100 Preparation of OH-lB: Same as in Example 1. gigggggiiltiitf (MW 550) i 3 1522 Properties of OH1B: Xykm NCO/OH 1/3 P d S Ex 1 1 Molecular weight 796 roce ame amp e Equivalent weight 199 Properties: Hydroxyl number 281 NCO/ OH 1/3 Percent hydroxyl 8.5 Average molecular weight 1280 OH-lB in urethane surface coatings: When employed g gi g i Welght V as the second component together with NCO-1 or i i 5 3 NCO-'3 in the NCO/OH proportions of Example 1, a Y m Y OH-IB gives urethane films which are less flexible but OH'l-lZ in urethane surface coatings: When employed which have greater solvent resistance than the films of as the second component together with N'CO-1 or NCO- Example 1. Chemical resistance and water immersion 3 in the NCO/OH proportions of Example 1, OH-IZ resistance are excellent. gives urethane films which are slightly more flexible but Exam le 4 which have slightly less solvent resistance than the films p of Example 1. Chemical resistance and water immer- (OH-lX) sion resistance are excellent.

Example 7 Reactants Moles Parts (OH-11) Phenylene diisocyanate 1 156 argarin atteasrtrrrttsst: M.W. 0130s (MW. 2. 700 35 Zsthoxyethyl 107 TDI so 20; 2,4 2,6 1 174 y 107 Addition product of 12 moles of propylene oxide to 2 o e mzl e of g lgg ezythritol (M.W. 840) 2 1, 52g -8 Preparation of OH-lX: Same as in Example 1. Xylpn P y Properties of OH-1X: 40

NCO/OH 1 3 Procedure: Same as in Example 1. Molecular weight 864 Properties: Equivalent weight -1 216 NCO/0H 4 Hydroxyl number 260 Average molecular weight 1860 Percent Y Y Average equivalent weight 310 OH-IX in urethane surface coatings: When employed. Hy number as the second component together with NCO-1 or Percent hydroxyl NCO-3 in the NCO/OH proportions of Example 1, 0H in p urethane surface coatings: When employed 3 1 glves urithanel i w i i 2 1}; as the'second component together with NCO-4 or NCO-3 3 1 F 5; en 1551s anced S in the NCO/ OH proportions of Example 1, OH-1P gives fi e resls ance an Wa er Immersw urethane films which are more flexible but which have resls ancea e exce e less solvent resistance than the films of Example 1. Example 5 Chemical resistance and water immersion resistance are excellent. (OH IY) Example 8 Reactauts Moles Parts (OH-11M) Diphenylmethane-4,4diis0eyanate 1 250 Reactants M l Parts Addition product of 4 moles of propylene oxide to one mole of pentaerythritol (P368TM.W. 368)-- 2 736 2-ethoxyethyl acetate 212 TDI (80/20; 2,4/2,6) 1 174 Xylene 212 Addition product of 4 moles of propylene oxide to one mole of trimethylolpropane (M-.W. 360) 2 720 2-ethoxyethyl acetate 118 Procedure: Same as 111 Example 1. Xylene 113 Prop 3223 1/4 Procedure: Same as in Exan rple 1. 7

Average molecular weight 984 Properties: Average equivalent weight 164 NCO/ OH 1/3 Hydroxyl number 342 Average molecular weight 894 Percent hydroxyl 10.3 Average equivalent weight 223 OH-IY in urethane surface coatings: When employed gydroxylh f 256 as the second component together with NCO-1 or NCO-3 ercent y oxy in the NCO/OH proportions of Example 1, OH-lY OH-lin urethane coatings: When employed as the gives urethane films which are less flexible but which have 7 5 second component together with NCO-1 or NCO-3 in 7 the NCOYOH proportions of Example 1, OH-IM gives urethane films which are less flexible but which have greater solvent resistance than the films of Example 1. Chemical resistance and ,waterimmersion resistance are excellent. h V w solvent resistance than the films of Example l Chemical Exampl'e 9 resistance and Water immersion resistance are good.

(CHAN) Example 12 Reactants Moles Parts (OH-1E1) TDI (s0/20; 2,4/2,s) l l 1 174 Reactants Moles Parts Pentaerythritol addition product with fourtpropye s lene oxide units and one ethylene oxide unit (M.W. i 410) p 2 S20 Diphenylmethane-4,4-diisocyanate 1 250 2-ethoxyethyl acetate 213 15 Addition product of'Q'moles of propylene oxide to ylene 213 one mole of trimethylolpropane (M.W. 660) 2 1, 320

getlhoxyethyl aepmtp y we... Procedure: Same asrin Example 1.

Properties: Procedure: Same as in Example 1.

' NCO/OH Pro rties' Average molecular weight 1000 1/3 Average eqlllvalentvwelght 167 Average molecular weight ...Q 15 62 Hydroxyl number 336 Average equivalent weight a 390 Percent y yl 10.1 .Hydroxyl number 4 OH-lN in urethane surface coatings: When employed P rc nt hydroxyl V 4.3 f g gfi g f g f Q OH-lET in urethane surface coatings: When employed e e s f gi gig iegs flig b Ml c i ls: as the'second component together with NCO1 or NCO-3 v in the NCO/ OH proportions of Example 1, OH-lET gives eater solvent resistance than the films of Exam 1e 1. t C hemical resistance and water immersion resistan e are urethane films vYhlCh are more flexlble but whlch have v less solvent resistance than the films of Example 1. excellent Chemical resistance and water immersion resistance are Example 10 good. (OH-1m) Example 13 Reactants Moles Parts TDI (80/20;2,4/2,6) Q H1 174 Reactants Moles Parts Weight, Addition product of 4 moles of propylene oxide to Percent one mole of hexanetriol (MlW. 350) 2 700 40 2-ethoxyethyl acetate 109 V Xylene 109 Polyoxypropylene derivative of triggtlgolpropane, 411, Pluracol 2'466 62 4 Procedure: Same as in Example 1. gz fig; 5'69?- ifDi Elli/2b? I 2etl1oxyethyl a et t 399 10' fi iiyoe 7 1/3 Kym c a e 399 Average molecular Weight 880 100") Average equivalent weight 220 V Hydroxyl number 255 NoTE.Ratio of reactive groups: NCO/OH=4/9=1/2.25. Percent hydroxyl 7,7 (In place of Pluracol TP-440, other trimethylolpropane a derivatives having 1-3 units of propylene oxide added to OH-1NX 1n urethane surface coatings. When employed 7 each hydroxy group may be used as the second component together with NCO1 or NCO-3 in the NCO/OH Proportions of Example 1, OH 1NX Preparation of OH-132: 2 466 parts of Pluracol Tl -440 gives urethane films which are less flexible but which have 696 Paris of tolylene du.socyanate are charged mm slightly g eater solvent resistance than the films of exi g g i 32 i g? g -i ample. Chemical resistance and water immersion resiste e 0 i was Ion mes O e ance are excellent w 7 blend 1s kept at fl'llS temperature for at least one hour until the exothermic reaction stops, whereafter 179 parts Example 11 of 2-ethoxyethyl acetate and 179 parts of xylene are 1 added in order to dilute the batch to 90% solids.

' The temperature isthen raised to 80 C. and the con- Reactants Moles Puts tents are heated for 3 hours a gentle stirring. The

viscosrties are measured each hour. 7 I Diphenylmethane- -diisocyanate I V V 1 a 250 Viscosity of the 90% solid batch reaches'z' Addition product of 12 moles of propylene oxide to I one mole of pentaerythritol (IVLW. 850) 2 1, 700 V Z-ethoxyethyl ace 415 Gardner Xylene 415 bubble Centistokes vlscoslimeter V rea mgs Procedure: Same as in Example 1.

t Art 1 th Y-Z 1,760-2, 270 011511165 Mtg; 22d fi r. Zg-Za 3, 390-4, 30 NCO/OH 1/4 After 3rd hour ZIFZK 6, 340-9, 850

Average molecular weight 1915 p Average equivalent weight 319 220 parts of Z-ethoxyethyl acetate and 220 parts xylene Hydroxyl number 176 are added in order to dilute the batch to 80% solids. The Percent hydroxyl 5.34 contents are bottled. a r

OI-I-l-EX in urethansurface coatings: When employed as the second component together with NCO-1 or NCO-3 in the NCO/ OH proportions of Example 1, QH-lEX gives urethane films Which are more flexible but which have less Properties:

NCO/OH l/2.25 Average molecular weight 1590 Average equivalent weight 318 Hydroxyl number 177 Percent hydroxyl 5.36 Properties of OH-132 solution:

Non-volatile, percent 80 Weight per gallon, lb. 8.86 Viscosity at 25 C., cps. 1000-3000 OH132 is more viscous and dries to touch faster upon evaporation of solvent than does the OH-l of Example 1. The solvent resistance is less satisfactory than that of Example 1.

TWO COMPONENT URETHANE COATINGS Formulation COMYOSITION Isoeyanateterminated intermediate a s Hydroxy-terminated intermediate-.

Parts NCO/OH PROPERTIES Pot life, hr Sward hardness Tensile strength, psi- Impact testGardner,

Direct Indirect Abrasion resistance, mg./1,000 cycles Chemical resistance Solvent resistance, hr.:

Toluene 3 2 2-ethoxyethy1 acetate 2 1 Methylisobutyl ketone 2 1 3, DOD-4,000

Over 30 Over 30 28 Very good 26 Very good .group consisting of phenylene diisocyanate, tolylene diisocyanate, and diphenylmethane-4,4-diisocyanate, with about two molar proportions of polyether polyol (b), said polyether polyol (b) being of the formula:

O '(G3HflO)nH wherein R with attached oxygen atoms represents the radical of a polyhydric lower-aliphatic alcohol, wherein n is a number from one to three, inclusive, and wherein x and z are individually numbers from zero to one, inclusive, to produce the desired hydroxy-terminated urethane composition, the initial reaction temperature being not greater than about sixty degrees centigrade.

2. A hydroxy-terminated urethane composition according to claim 1, wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is an alkylene oxide addition product of trimethylolpropane.

3. A hydroxy-terminated urethane composition according to claim 1 wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a pentaerythritol alkylene oxide addition product.

4. A hydroxy-terminated urethane composition according to claim 1 wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a hexanetriol alkylene oxide addition product.

5. A hydroxy-terminated urethane composition accord ing to claim 1 wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a glycerine alkylene oxide addition product.

6. A hydroxy-terminated urethane composition accord ing to claim 1 wherein the average equivalent weight is between about 200 and about 400.

7. A solution of a hydroxy-terminated urethane composition according to claim 1 in a surface coating solvent which is non-reactive therewith.

'8. A urethane coating composition including as one component a hydroxy-terminated urethane composition according to claim 1 and including an organic polyisocyanate as a second component.

9. A coating composition according to claim 8, including an organic surface coating solvent which is nonreactive with both the components of the coating composition and their polyurethane reaction product.

10. A process for the production of a hydroxy-terminated urethane composition which comprises mixing and reacting together about one molar proportion of arylene diisocyanate (a) selected from the group consisting of phenylene diisocyanate, tolylene diisocyanate, and diphenylmethane-4,4'diisocyanate, with about two molar proportions of polyether polyol (b), said polyether polyol (b) having the formula:

wherein R with attached oxygen atoms represents the radical of -a polyhydric lower-aliphatic alcohol, wherein thane composition according to claim 10, wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is an alkylene oxide addition product of trimethylolpropane.

12. A process for producing a hydroxy-terminated urethane composition according to claim 10, wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a pentaerythritol-alkylene oxide addition product.

13. A process for producing a hydroxy-terminated urethane composition according to claim 10, wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a hexanetriol-alkylene oxide addition product.

14. A process for producing a hydroxy-terminated urethane composition according to claim 10, wherein the arylene diisocyanate (a) is tolylene diisocyanate and the polyether polyol (b) is a glycerine-alkylene oxide addition product.

15. A novel branched hydroxy-terminated polyetherbased urethane composition produced by mixing and reacting about one molar proportion of an arylene diisocyanate selected from the group consisting of tolylene diisocyanate, phenylene diisocyanate, and diphenylmethane- 4,4'-diisocyanate, with about two molar proportions of a polyether polyol which is a propylene oxide addition product of a polyhydric lower aliphatic alcohol having at least three and not more than four hydroxy groups in the molecule, said polyol having at least one and not more than three propylene oxide units per hydroxyl group.

16. A process for the production of a novel branched hydroxy-terminated polyether-based urethane composition, which consists in mixing and reacting about one molar proportion of an arylene diisocyanate selected from the group consisting of tolylene diisocyanate, phenylene diisocyanate, and diphenylmethane-4,4'-diisocyanate, with 1 1 about two molar proportions of a polyether polyol which is a propylene oxide addition product of a polyhydric lower aliphatic alcoholhaving at least three and not more than four hydroxy groups in the molecule, said polyol having at least one and not more than three propylene 0xide units per hydroxyl group.

References Cited in the file of this patent UNITED STATES PATENTS 12 V McShane Ian- 27, 1959 Windemuth July 28, 1959 Croco Aug. 25, 1959 Windemuth et a1 Aug. 9, 1960 FOREIGN PATENTS Australia Jan, 4, 1957 Australia Feb. 10, 1955 OTHER REFERENCES Abernathy: Rubber World, March 1955, vol. 131, N0. 6, pages 765-769.

Ogden: Rubber World, July 1957, pages 537-542.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,049,515 August 14, 1962 Adolfas Damusis It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 8, after "of" insert a line 45, for "ractive" read reactive column 4, line 6, for "urethant" read urethane same column 4, footnote 1 of the first table, line 4 thereof, for "DI" read MDI column 5, table of Example 5, column 1, line 1 thereof, for "4,4-" read 4,4- column 6, line 74, for "OH-l" read OH-lM Signed and sealed this 16th day of April 1963.

(SEAL) Attest:

ERNEST w. SWIDER DAVID LADD ing Officer Commissioner of Patents 

1. A HYDROXY-TERMINATED URETHANE COMPOSITION PREPARED BY MIXING AND REACTING TOGETHER ABOUT ONE MOLAR PROPORTION OF ARYLENE DIISOCYANTE (A) SELECTED FROM THE GROUP CONSISTING OF PHENYLENE DIISOCYANTE, TOLYLENE DIISOCYANTE, AND DIPHENYLMETHANE-4,4''-DIISOCYANATE, WITH ABOUT TWO MOLAR PROPORTIONS OF POLYETHER POLYOL (B), SAID POLYETHER POLYOL (B) BEING OF THE FORMULA: 